Note: This game is also known as - Gouma Reifu Den Izuna Ni

Bonus dungeons - Successfully complete the main story line to unlock the following dungeons:

Girls Only dungeon: Located at the shrine near Himiko.
Mugen Chasm dungeon: Located where Shizune ran to.
No Item dungeon: Located at Surei Town. The Gankatsu talisman is required.

Bonus characters - Successfully complete the main story line, then talk to the following bonus characters at the indicated locations:

Gen-An
Himiko at Kamairi Village
Hinagiku at Mugen City
Ichika at Surei Town. You must first unlock the No Item dungeon.
Suzuri at Kamairi Village